My engine has no power why?

This sounds like a typical fuel pump which are common on these cars. Here is a fuel pressure test and can do to confirm the issue the pressure should be between 56 and 62 psi:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Please run down this guide and report back.

Cheers

The pressure is 43.5 pounds. So is the pump bad?

Yes, the pump is bad. You can get a new one from Amazon for about $120.00 Ac Delco. Here are guides to help you see what you are in for when changing the pump out with diagrams to show you how it will be on your car:

https://www.2carpros.com/articles/how-to-replace-an-electric-fuel-pump

Check out the diagrams (below). Please let us know what happens.

Well that was a job but I did it. The ruck has never run better. Thanks to all who helped. I love this site.

Nice work, we are here to help, please use 2CarPros anytime.

Cheers

The effects:
Lose of power/choking/backfires if i try to put the gas on. I have noticed I have lost major power anyways.
From this v8 now then when I bought it (used).

Before (cold start) no issues. Until the truck warms up after one hour? driving, if I push the gas in to go hard, it has this BAM no power. Nothing if I force the gas in even when I know I am getting 0 power out of it, (feels like it goes into neutral) it has baby back fires. When I let off the gas, push in 20% it has some what enough power to drive down the street. So when I take off, or even go anywhere, I cannot push the gas in much or it will just choke.

Only way I figured out how to fix its self (before) was to just shut it off for few minutes. Then I found out I can shut it off for five seconds until computer resets and re start it - (before) I got power and no choking.
But now, even after two hours of driving, rebooting (shutting off) does not help 50/50 of the time.
It is getting worse after two weeks now?

Prior to this happening, I used to drive only in third.
Then I started to just drive in (D). Started to have check light come on. Then it goes off. Second time it came on got it checked out. O2 Position 1 and 2 sensor is bad. Then light goes back off. Only three times this has came on, no I have not changed them.

No, I have not did a tune up, or changed anything.
Not put any fuel cleaner in or nothing.

Could be fuel pressure related, or TPS(throttl possition sensor) test like this. https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Use a volt meter and check TPS should be smooth, no spikes in voltage and no binding. When was the last tune up?

Well with these symptoms it might be the VSS (vehicle speed sensor). Is the service engine light on? If so go to AutoZone, they will read the codes free, post results here.

I figured out the 2wd/4wd issue..
After hitting bumps in the road and
all that. The darn plug wire was lose.
Took off the dash and pushed hard.
Never had an issue since.

For the gas/losing power issue.
No clue yet. With money problems
and time, I have not yet to fix it.
Very soon and when I do I will come back
and update.

Until then, I am thinking fuel pump again.
Or, fuel regulator might be it.
The whole choking is making me wonder.

No light is on. o2 only problem coming up.
Yes, I did get tune up done. Wires,
plugs, fuel filter, cap, rotor 9 yards,
Still no difference.

However..
He did clean my carburetor, that did seam
to help for twenty minutes.
I have bought five fuel tank treatments. four carburetor cleaner and one Injector cleaner.

I have also noticed full tank, issue is worse then only having 1/4 tank.

Test the fuel pump pressure as described above.
Check catalytic converter, may be partially plugged, use a vacuum gauge and bring rpm to 2000, hold steady, if gauge starts to drop from 18-22 hg then exhaust is plugged. If you are having hot weather where you are, it could be fuel related, you could have winter blend fuel and if you run with low fuel tank, it could be causing a capitation in the fuel pump, (vapor lock). Keep tank full and test.

My truck lost power while driving at 35-40 mph. It seemed to lose power for a couple of seconds and then come back for a few seconds. It did that a couple of times before it lost complete power to the engine and all power components. Is this likely to be the fuel pump?

Thanks for the help!

Have you ever done any work on the fuel pump or the gas tank? Check the fuel pressure. If you cannot do this autozone or a place like that usually will do this for free. If not they will loan you a pressure gauge so you can do it. Let me know what it is.

Ok, got it in the shop!
Paid 26$ for them to tell me my Cat*
Is ok. Nothing wrong with it. My fuel (PSI)
Is low. i think 50s? So i replaced my Fuel
filter.. Black gunk came out. Still no fix!

Regulator on a 99 Chev Tahoe - No idea
where it is.. But what i have seen it was dry.
The uh, Hose was dry. 55$ part i will be replacing
in few days. But still losing power and getting worse!

When i replace the GD fuel pump (250 part + 100)
and if thats what it is i will let everyone know..
And since iv been seeing about how shity this
truck is with the fuel pump issues, im guessing this
is what it is. But in time like this with money,
this will be hard to pay for. But im sure thats what
it is the whole time.

Well low pressure will give you these symtoms, so wont clogged injectors...if any of that black goo made it past your old filter.

Yeah, i went to buy a Fuel pressure regulator.
Went to put it in, but yet i dont have fuel lines..
I found out i have the other type of engine.
SO....

I found out i have to take off the top man/fold
And thats going to take more money..
So...

I hope its just the Fuel pump. And im thinking
it is and it would be cheaper at this point because
from what i hear Fuel pumps go out on these trucks
a lot for some reason...

The other thing you could check is, you said it's fine when cold? If so check the ect(engine coolant temp) sensor, if it's off, it can produce symtoms like this too.

Ok.. So my cable went down the day before i fixed
what it was this whole time!!

I was correct the whole time!!!
Fuel pump.. FUEL PUMP! OMG! DAM FUEL PUMP!

Ok, i did EVERYTHING to the POS before i changed the
Fuel pump... As the following..

Computer numbers always first..
Cats , Plugs/Wires/cap/rotar, Fuel filter (changed)
Air filter, Idle control Censer, Vacuum lines,
Throttle body censer, Fuel pressure regulator (Changed)
EGR Valve cleaned, Fuel line cleaned, Top Manifold Cleaned,
im sure there is more i did to it. 3-4 months of checking,
Fixing things and all along i knew what it was..
But everyone was trying to stay away from what it was.

after many hours and money..... FUEL PUMP!!!!!!

Symptoms =
Starts up fine, NEVER ever starting issues!
Cold start - Idles fine, Takes off fine, Driving
and it starts to get less pressure = loss of power.
Then it will act like theres no fuel no power, then
as letting off the gas the idle is fine!

I hope this helps anyone else with the issue of the
Chevy (Tahoe) aka POS on this issue.

Over the last month my 99 5.7 4WD Tahoe has been giving me problems accelerating when I give it a heavy foot. When I hit the gas down it loses acceleration almost like it's being starved of air or gas. When I hit the gas the engines just bogs down, begins to hesitate, and will not accelerate.

It'll drive ok if I'm light on the pedal; and the engine feels smoother than ever.

i already replaced the mass airflow sens, plugs and cables, egr valve, distributor, and air sensor, my fuel pump is about 4 yrs old and my fuel filter is 5 months old.

i get all this but my check engine light does not come on ....only my service engine soon light turns on

I think I told you that three or four times...happy motoring anyway!

The service engine soon light indicates that a trouble code is set in the computer. Have the computer scanned or scan it yourself and retreive trouble code. Autozone or a place like that will scan your computer and give you the code for free. This code will lead us to the area of the problem..
What type of air filter do you have? Why did you change the mass air flow sensor? What brand name plugs and wires did you install? Is there good exhaust flow at the tail pipe?

Runs starts and idles great just sluggish when ya press on gas no codes and no engine light changed tps fuel filter and air filter also tried the mass air flow sensor off my dads Tahoe all this with no change in issue sluggish off idle wont rev over 3000 rpm proper fuel pressure and exaust seems to flow proper and sounds normal tomorrow afte work I plan to pull the two pre cat o2 sensors to see if increase flow helps how it runs

check fuel pressure with a gauge first should be 50-60 with key on engine off

Have a 99 Chevy Tahoe with 350 auto 4x4 starts and will idle fine but will not rev over 2500-3000 rpm starts to stumble no codes and no check engine light drives like a champ untill u need more than 1/4-1/2 throttle then falls on its face I installed new air filter and fuel filter please help !

Test the fuel pressure while this is happening. This system requires a minimum of 55PSI to run.

Ok pulling out of work today it stumbled and had no power from idle all the way through the rpm range got home hooked up fuel pressure tester and reads 55-65 psi at all ranges of throttle then on my way to the store I jumped on it and ran like a champ tranny kicked down and took off and now sitting in park will rev past the 25-3000 mark no problem Could this issue be with a faulty tps sensor?

Ok i have a 1999 chevy Tahoe with 186000+ miles, i recently changed out the catalytic converter, and both upstream and downstream O2 sensors about a week ago. just yesterday i did a major tune up replacing the Distibutor, rotor cap, oil change, plugs, wires, thermostat, egr, pcv and air filter. in hopes of getting my gas mileage up back where it was. Now the problem im having is after the catalytic converter was changed out my truck has been having these power problems when i turn on the heater or rear defrost my battery drops out pretty signifigantly. i told the mechanic about the problems i was having and he told me that the problems i speak of with the heater is normal, not to worry about it and he went ahead and did the tune up with the parts i got for the truck. Now a day latter my battery practically is completely drained but has enough power to keep the light in the cab and the lamps on the dash and headlights on, head lights are on dim though. i tried turning the engine over but when i crank it i just keep getting this clicking noise like the truck doesnt want to turn. do anyone know what might be the problem or cause of the draw back of power from the truck??

I also have a 1999 tahoe which i love and I have replaced the battery 3 times since I purchased it used (2006- 50,000 miles). Each time it seems like the battery dies due to lights left on and then I can never recover the battery. Last week i left the lights on and jumped it off the next morning. Well I looked at the battery and it was dirty so i cleaned it up good figuring the alternator wasnt able to charge it well. And now its even worst. I just drove it about 30 miles and parked it hoping it would have charged. However, cut it off then tryed to crank it ..... still having a problem starting. Any idea why this is happening? I also have replaced the alternator as well. It seems like I have a bad connection somewhere. I have had trouble with the interior lights flashing on and off too. This has occured a few months ago though.
HELP. Do i just need to get another battery?

I have a 1999 chevy tahoe and when i go to take off the radio cuts off, when i turn on the lights the radio cuts off, when i hit the brake pedal radio cuts off, or uses the wipers it cuts off, an even with all these things the truck acts as if its wanting to turn off. The power continuies like that when im driving it does it when it want to. Hopeing you can help me find what the problem may be .

THis is interesting. Have you checked to make sure all grounds are in good condition and tight?

Check engine compression may have faulty intake valve

checked compression with my gauge they were all around 100lbs

If gague is working compression WAY low should be 150-175 I'm surprised it runs. Have you checked for timing stretch ie. wear and lots of play ?

don't think gauge is accurate but they were all even. starts and idles to good no miss at idle

i have a 1999 tahoe with 5.7 motor was rebuilt about 30000 miles ago. i have trouble starting it takes a few tries or will fire up with gumout. after it starts it will bogg down or almost die out if i hit the gas to hard or to far. i have tried doing plugs, wires, cap, and rotor. the fuel pump was replaced a few months ago. replaced mass air flow sensor and it made no difference. any ideas would be a great help

have you checked to see if the fuel pressure regulator on the intake was leaking or not.

i think i am having the same problem. if you press the trhottle does it die?

Does it free rev and the transmission does not want to shift? Almost like you have no 3rd gear or does it go when you stomp on the gas but still runs like crap?

That's what I am dealing with now

not any more mine will do no more than idle. at a loss
bout to give up on the tahoe

replace the fuel pump it will be just fine

140,000 5.7. 4x4. I have a problem at acceleration. Very low power. When i hit the gas from a complete stop it acts like its starving for air or flooding?? A good example of what is happening is, picture a manual transmission car starting out from a dead stop in 3rd gear. Once the tahoe gets to a certain RPM (2nd gear) it takes off like a raped ape. I mean it sits you right back in your seat. On the highway or in normal traffic, it has no hesitation or lack of power. Plenty of get up and go when passing. I have replaced the plugs, coil, Cat convertors, fuel filter, checked and cleaned EGR valve, checked air filter, and had to replace 1 O2 sensor because it was damaged while replacing the cats. NO TROUBLE CODES. I dont want to sink any more money into this and guessing what is wrong. It is an awsome looking and running vehicle other than this problem. It is also getting terrible fuel economy.